Contact mixer



DEC. 18, 1 A REED CONTACT MIXER Filed Feb. 26, 1952 United States PatentOtlice g CONTACT MIXER John Alva Reed, Glossop, England, assignor, bymesne assignments, to Tootal Broadhurst Lee Company Lim vited,Manchester, England, a British company Application February 26, 1952,Serial No.1273,440

Claims priority, application Great Britain March 1, 1951 The presentinvention relates to the treatment of one substance with another, ofwhich at least one is a liquid, and includes the treatment of a solidwith a liquid, for example to wash the solid with the liquid andincludes the mixing of a liquid with a solidor a liquid by which 6Claims.

2,774,654 Patented Dec. 18, 1956 i Referring especially to Fig. 1, acylindrical tank 1 is mounted on a stand 2 of tubular construction andcontains ak concentric cylindrical partition 3 spacedfrom thecylindricalwall of the tank to define au outer ow chamber' 4. The upperend of said cylindrical partition 3 lies below Ithe level of the top ofthe tank and the lower end of the said cylindrical partition 3 islocated above the bottom of the tank and merges into or is connectedwith an inwardly extending lower partition 5 which in turn merges intoor is connected with an upwardly extending central passage element 6which, with the partition 3 f defines an inner flow chamber 7surrounding the central is meant either the dissolving of a solid in aliquid or s passage element 6. The central passage element 6 rises to alevel above the top of the tank and is of downwardly convergent conicalform. Openings 8 are formed in the centralipassage element 6'below thelevel of the upper 'end of said cylindrical ypartitionV 3 to enableliquid to flow from the inner'ow chamber 7 into the central passageformed by the'element 6.

The bottom of the tank and the partition 5 define a connecting spacethrough which liquid can ow from the f central passage to the outer flowchamber 4.

upon it is allowed to ilow inwardly and downwardly in centrifuged.

If desired the liquid may be subjected to interchange of heat in orderto heat or cool the same during its llow f through said closed circuitand preferably during its ascent in said first mentioned annular stream.

Preferably the liquid is caused to flow in a turbulent manner throughpart of said closed circuit and especially during its ascent in saidmore or less annular stream where it may be heated or cooled. Suchturbulent flow may be achieved by suitably adjusting the rate ofcentrifuging of the liquid.

The liquid, whilst moving towards that portion of its path of travelwhere it ascends in said more or less annular stream may be restrainedagainst undue rotational movement as a result of the centrifugingthereof andit may also be restrained against undue rotational movementwhilst ascending in said annular 'stream.

The liquid may be sieved or'ltered duringV itsfpath lof travel in ordertol restrain movement of solid 'matter Vwith the liquid. For'ex'ampl'eit may besieved immediately after it has been centrifuged. ,l

An apparatus according to the present invention consists of acentrifugal impeller located at or adjacent the lower end ofpa centralvpassage `or chamber which central passage or chamber is surroundedbyfa'ninner ilowr chamber which in turn is surrounded by an outer flowchamber, said flow chambers being in communication with one anotheratrtheir upper ends and `said -outer flowchamber and saidcentral passage`being in communicationat-their lowerl ends whilst the inner ow chamberand said central passage communicatewith one another below Vthe level ofthe upper Aend 'of the inner flow chamber.'

An impeller shaft 9 passes centrally through the central passage element6 andis. journalled in upper and lower bearing assemblies 10, 11 securedrespectively to the tubular frame 2 and to the bottom of the tank. Theimpeller shaft 9 is driven by an electric motor 12 through belts 13 andbelt pulleys 14, 15.

AThe impeller consists of a set Yof outwardly extending curved blades 16(Fig. 3.) secured between lower and upper coverpla'tes 17, 18 (Fig. l)of which the lower cover plate 17 is secured by screws 19 to a boss Ztlwhich is welded to the shaft 9.

The impeller is of the type which is fed more or less axially atits'centrea'nd ydischarges more or less radially at its periphery andtheupper cover plate 18 has a central opening which permits ingress ofliquid into the impeller.

A set of stationary vanes 4or baffles 21 (Figs. l and 3) extend' awayfrom the periphery of the impeller through the said connectingspace'leading from the impellery to the outer ilow chamber 4. e Thepurpose of these vanes 21 is to prevent undue rotational movement of theliquid after leaving the impeller. The tank is provided with a drainageoutletr22 in its bottom and a small hole is provided in theouterpart ofthe partition 5 to enable liquid in the lower part ofthe inner flowchamber to drain therefrom.

A downwardly ldirected chute: 23 enters the central passage element 6 ata level nearL the upper end of the inner flow chamber. l y

A tubular coil 24 is arrangedin the outer flow chamber 4 and its ends25, 26 can be connected Vwith a source of heating medium or with asource of cooling medium or they can be alternatively connected withvone or the other ticontrolthe'temperature of the liquid.

The said coil 24 is supported in the outer ilow chamber 4'by rising baleelements 27 -in the form offlat plates which extend across th'e outerflow chamber vand thereby The said 4 inner and o uter Yllow chambers arepreferably of annular forrnrandnsaid centralpassage ispreferablyofdownwardly-.convergent conicalform'with the centrifugalimpeller disposed inrtherspace which vconnects the' lower end-,offsaidcentralpassage with the .outer flow chamber.

'.The inventionis.furtheri described by way of vexample with referenceto the accompanying drawings, in which:

Fig. l is a part sectional side elevation,

A Fig Zisaplan viewand ,A Y I, f i

Fig. l. w

' Theiny'entionlis particularly suitable for the preparation of urea'formaldehydecondensation products; For

this purpose a quantity of `formaldehyde solution (formalin) is-fedlintothe tank and the impeller is caused to rotate to 'cause' the liquid tomove outwardly from the Virnpeller, through the guide vanes 21, then toascend through Y and together with the formalin is passed by theimpeller outwardly from the lower end of the passage element.

In the preparation of urea formaldehyde condensation products theimpeller may be rotated at about 3.00 revolutions per minute.

The mixing of the urea with theV formaldehyde solution gives rise to anendoth'ermic reaction which reduces the temperature of the mix toaboutOu C. An ammonia solution is then added to the mix Vgiving rise toa mild exothermic reaction. Steam may be passed through the coil 24 toraise the temperature of the mix to say 30 C. whereafter the temperaturemay be maintained substantially constant by passing either steam'through said coil to heat it or water in order to cool it.

An alternative use for the apparatus of the present invention may be forthe dissolving of caustic soda in butanol to produce an alkalinereagent, Vthe tank being first charged with butanol, and caustic sodabeing fed through the chute 23 when the butanol is in circulation asdescribed above with reference to formalin. Y Y

In certain applications of the invention to the dissolving of a solid ina liquid it may be an advantage to provide a sieve or filter immediatelysurrounding'the impeller. In this way fragments of soluble solid mattercan beheld back at the periphery of the impeller where they can besubjected to the dissolving action of the liquid moving at relativelyhigh speed under the centrifugal action of the impeller. The grid ormesh can be stationary but is preferably secured to the periphery oftheimpeller so as to rotate therewith. The size of the mesh should bechosen in relation to the nature of'and size of the fragments of solidmatter to be dissolved with a view to achieving a maximum tendencyV forthe solid matter to become dissolved without undue risk of completelyblocking up vthe mesh. A'

the impeller to connect the central passage element with the inner flowchamber.

2. Apparatus acording to claim 1 including a driving shaft for saidimpeller extending upwardly through said central passage element andlower bearing means for said shaft within the tank and upper bearingmeans for said shaft located above the top of the tank.

3. Apparatus according to claim 1 including a tubular coil in the outerflow chamber for controlling the temperature of the liquid. Y

4. Apparatus according to claim 1 including rising bafe elementsextending across the width of the outer flow chamber to restrainrotational movement of the liquid whilst owing through said outer owchamber.

5. An apparatus for treating one substance with another of which atleast one is a liquid comprising a cylindrical tank, a central passageelement rising from a level above the bottom of the tank to a levelabove the top of the tank, a cylindrical partition within the tanksurrounding said central passage element with its upper end below thetop of the tank and its lower end above the bottom of the tank to denean outer flow chamber between itself and the cylindrical wall of thetank and to define an inner flow chamber between itself and said centralpassage element, a lower partition extending from the lower end of saidcylindrical partition to the lower end of said central passage elementto define between itself and the bottom of the tank a connecting spacebetween the central passage element and the outer flow chamber, saidcentral passage element having at least one opening therein below themid-height of said cylindrical partition to y connect the centralpassage element with the inner ow The apparatus of the present inventionmay alsolbe used for the liquid treatment of certain manufactured goodse. g. socks, which may be held in a cage or basket of annular formlocated in the outer flow chamber 4 or in the inner iiow chamber 7. SuchaV cage or Ybasket should have a perforate top and bottom to permitpassage of the washing or other liquid therethrough.

I claim:

1. An apparatus for treating one substance with auother of which atleast one is a liquidcomprising a cylindrical tank, a central passageelement rising from a level above the bottom of the tank to a levelabove the top of the tank, a cylindrical partition within the tanksurrounding said central passage element with its upper end below thetop of the tank and below the top of the central passage element and itslower end above the bottom of the tank to define an outer ow chamberbetween itself and the cylindrical wall of the tank and to dene an innerflow chamber between itself and said central passageelement, a lowerpartition extending from 'the lower end of said cylindrical partition tothe lower end of said central passage element to dene between'itself andthe bottom of the tank .a connecting space between the central'passageelement and the outer flow chamber, and an impeller located in saidconnecting space immediately beneath the central passage element, saidcentral passage element having at least one opening therein below themid-height of said cylindrical partition at a level above chamber, animpeller located in said connecting space immediately beneath thecentral passage element, said impeller being of the kind which is fedsubstantially axially at its centre and discharges substantiallyradially at its periphery and comprising an upper cover plate and alower cover plate and a plurality of downwardly extending curved bladessecured between said cover plates of which the upper has a centralopening therein to permit ingress of liquid into the impeller, a set ofstationary vanes extending away from the periphery of the impellerthrough said connecting space towards the outer ow chamber for thepurpose of preventing undue rotational movement of the liquid afterleaving the impeller, rising baffle elements extending across the widthof said outer flow chamber to restrain rotational movement of the liquidwhilst owing through said outer flow chamber and a tubular coilsupported by said baffle elements. l I

6. An apparatus according to claim 5 and includingl a grid surroundingand mounted on the impeller so as to rotate therewith for the purposeyof holding back fragments of soluble solid matter at the periphery ofthe impeller.

References Cited in the filel of this patenti UNITED STATES PATENTS611,432 Katzenstein Sept. 27, 1898 1,211,828 Dorr Jan, 9, 1917 1,309,219Ruth July 8, 1919 1,678,787 Remick `Tuly 31, 1928 1,734,747' Seeley Nov.5, 1929 1,953,022 McCombs Mar. 27, 1934 2,031,788 Persoons Feb. 25, 19362,085,492 Ellis June 29, 1937 2,430,180 LeGloahec Nov. 4, 1947 2,458,261Green et al. Jan. 4, 1949 2,467,212 Kvalnes l Apr. 12,y 1949 2,617,334Kolb et al. Nov. v11, 1952 FOREIGN PATENTS 550,990 Germany May 24, 1932609,091 Great Britain Sept. 24, V1948 788 Switzerland Apr. 24,1889

1. AN APPARATUS FOR TREATING ONE SUBSTANCE WITH ANOTHER OF WHICH ATLEAST ONE IS A LIQUID COMPRISING A CYLINDRICAL TANK, A CENTRAL PASSAGEELEMENT RISING FROM A LEVEL ABOVE THE BOTTOM OF THE TANK TO A LEVELABOVE THE TOP OF THE TANK, A CYLINDRICAL PARTITION WITHIN THE TANKSURROUNDING SAID CENTRAL PASSAGE ELEMENT WITH ITS UPPER END BELOW THETOP OF THE TANK AND BELOW THE TOP OF THE CENTRAL PASSAGE ELEMENT AND ITSLOWER END ABOVE THE BOTTOM OF THE TANK TO DEFINE AN OUTER FLOW CHAMBERBETWEEN ITSELF AND THE CYLINDRICAL WALL OF THE TANK AND TO DEFINE ANINNER FLOW CHAMBER BETWEEN ITSELF AND SAID CENTRAL PASSAGE ELEMENT, ALOWER PARTITION EXTENDING FROM THE LOWER END OF SAID CYLINDRICALPARTITION TO THE LOWER END OF SAID CENTRAL PASSAGE ELEMENT TO DEFINEBETWEEN ITSELF AND THE BOTTOM OF THE TANK A CONNECTING SPACE BETWEEN THECENTRAL PASSAGE ELEMENT AND THE OUTER FLOW CHAMBER, AND AN IMPELLERLOCATED IN SAID CONNECTING SPACE IMMEDIATELY BENEATH THE CENTRAL PASSAGEELEMENT, SAID CENTRAL PASSAGE ELEMENT HAVING AT LEAST ONE OPENINGTHEREIN BELOW THE MID-HEIGHT OF SAID CYLINDRICAL PARTITION AT A LEVELABOVE THE IMPELLER TO CONNECT THE CENTRAL PASSAGE ELEMENT WITH THE INNERFLOW CHAMBER.